If you bet 2/3 pot and your opponent calls. You will probably be in very difficult situation in river.

There is much bad cards you don't wan't to see in river. like any
, 3, 6, A

So I would say it is easier to shove in turn.

The reason is that only a very loose opponent would Call there with some draw but we want him to make the mistake and Call there if we bet smaller and we also have a lot of outs what could help us. Flushdraw, 2pair type of hands or trips or whatever. I wouldn't be that worried about that.